Heater of heat storage agent and brayton solar thermal power unit with heat storage

Abstract

The present disclosure describes a heater of heat storage agent and a Brayton solar thermal power unit with heat storage. The Brayton solar thermal power unit with heat storage may include: a heat storage agent flow adjusting module, a solar energy collecting module, a heater of heat storage agent, a heat exchange module, a thermal power generating module a heat storage agent transporting module. The heat storage agent flow adjusting module may be connected with the heat storage agent transporting module and the heater. The heater may be connected with the solar power collecting module, and the heat exchange module. The heat exchange module may be connected with the thermal power generating module and the heat storage agent transporting module. The present disclosure can significantly increase maximum power capacity of Brayton solar thermal power unit to megawatt level, improve operation efficiency, and avoid discontinuity and instability of solar power generation.

The invention claimed is: 
     
       1. A heater of heat storage agent, comprising: a feeder, a threaded screw sleeve and a heat storage agent collector, wherein
 the feeder is provided at an upper part of the heater, capable of receiving heat storage agent discharged from above the heater and discharging the heat storage agent into the threaded screw sleeve; 
 the threaded screw sleeve is provided at the middle of the heater of heat storage agent, comprising a multi-threaded screw sleeve made of high temperature materials, the multi-threaded screw sleeve comprises a hollow interior, a plurality of spiral slideways are provided in an inner wall of the multi-threaded screw sleeve for receiving the heat storage agent discharged from the feeder and directing the heat storage agent to fall along the spiral slideways; a falling speed of the heat storage agent in the spiral slideways is adjustable by adjusting a rotation speed of the multi-threaded screw sleeve; the hollow interior is capable of housing concentrated solar radiation outputted by an external solar energy collecting module and heating the heat storage agent discharged into the multi-threaded screw sleeve using the concentrated solar radiation; and 
 the heat storage agent collector is provided at a lower part of the heater, capable of receiving the heat storage agent heated and discharged from the rotating multi-threaded screw sleeve and outputting the heated heat storage agent. 
 
     
     
       2. The heater of  claim 1 , wherein the threaded screw sleeve further comprises: an insulation sleeve made of a heat insulating material and a shell for a rotating part of the heater, wherein
 the shell is provided outside the threaded screw sleeve; 
 the rotating multi-threaded screw sleeve is provided inside the threaded screw sleeve; and 
 the insulation sleeve is provided between the multi-threaded screw sleeve and the shell, for thermal insulation of the heat storage agent. 
 
     
     
       3. The heater of  claim 1 , wherein the spiral slideways are uniformly distributed along the direction of diameter of the rotating multi-threaded screw sleeve, and the rotating multi-threaded screw sleeve rotates in a direction the same with or opposite to the helix direction of the spiral slideways. 
     
     
       4. The heater of  claim 1 , wherein a helix angle of the spiral slideways is between 5 to 85 degrees. 
     
     
       5. The heater of  claim 1 , wherein a width of the spiral slideways is 3 to 20 times of a diameter of the heat storage agent. 
     
     
       6. The heater of  claim 1 , wherein the heat storage agent comprises ceramic microspheres. 
     
     
       7. A Brayton solar thermal power unit with heat storage, comprising: a heat storage agent flow adjusting module, a solar energy collecting module, a heater of heat storage agent, a heat exchange module, a thermal power generating module and a heat storage agent transporting module, wherein
 the heat storage agent flow adjusting module is configured to adjust flow of heat storage agent flowing into the heater according to an intensity of solar radiation outputted by the solar energy collecting module; 
 the solar energy collecting module is configured to collect solar energy using at least one concentrator, and heat the heat storage agent in the heater using the collected solar energy; 
 the heat exchange module is configured to perform heat exchange between heat storage agent discharged from the heater and compressed air from the thermal power generating module, output the compressed air after the heat exchange to the thermal power generating module, output the heat storage agent after the heat exchange into the heat storage agent transporting module; 
 the heat storage agent transporting module is configured to collect the heat storage agent discharged by the heat transferring module, transport and output the collected heated storage agent to the heat storage agent flow adjusting module; and 
 the thermal power generating module is configured to convert thermal energy of the compressed air from the heat exchange module into mechanical energy, convert the mechanical energy into electrical energy, and output exhaust gas; compress air taken in under atmospheric pressure and output the compressed air to the heat exchange module; 
 wherein the heat storage agent adjusting module comprises: a hopper, a discharge tank, a discharge valve, a storage tank, and a flow control valve, wherein 
 the hopper is configured to discharge heat storage agent collected by the heat storage agent transporting module into the discharge tank; 
 the discharge tank is configured to store heat storage agent discharged by the hopper; 
 the discharge valve is provided at the bottom of the discharge tank, is configured to adjust the flow of the heat storage agent discharged from the discharge tank to the storage tank; 
 the storage tank is configured to store the heat storage agent discharged from the discharge tank via the discharge valve; and 
 the flow control valve is provided at the bottom of the storage tank, and is configured to adjust the flow of the heat storage agent in the heater according to an intensity of solar radiation outputted by the solar energy collecting module. 
 
     
     
       8. The Brayton solar thermal power unit of  claim 7 , wherein the heat storage agent comprises ceramic microspheres. 
     
     
       9. The Brayton solar thermal power unit of  claim 7 , further comprising: a split range control module, configured to sense a temperature of the heat storage agent outputted by the heater, compare the sensed temperature with a pre-determined temperature threshold; if the sensed temperature is inconsistent with the pre-determined temperature threshold, adjust a rotation speed of the rotating multi-threaded screw sleeve to change a falling speed of the heat storage agent in the heater, and adjust an opening of the flow control valve to change the flow of heat storage agent in the heater, until it is determined the sensed temperature is identical to the pre-determined temperature threshold. 
     
     
       10. The Brayton solar thermal power unit of  claim 7 , wherein the heat exchange module comprises a heat storage agent storage tank, a discharge adjusting valve and an air heater, wherein
 the heat storage agent storage tank is configured to store the heat storage agent discharged by the heat storage agent collector of the heater; 
 the discharge adjusting valve is provided at the bottom of the heat storage agent storage tank, is configured to adjust the flow of the heat storage agent discharged into the air heater from the heat storage agent storage tank; and 
 the air heater is configured to heat compressed air with a first temperature inputted by the thermal power generating module using the heat storage agent discharged by the heat storage agent storage tank to generate compressed air with a second temperature higher than the first temperature, and feed the compressed air with the second temperature back to the thermal power generating module. 
 
     
     
       11. The Brayton solar thermal power unit of  claim 10 , wherein the air heater comprises: a particle entrance component, a row of air heating pipes, connecting pipes joining the air heating pipes, and air entrance and exit pipes; wherein
 the particle entrance component is provided at the top of the air heater with a high-temperature particle moving bed, comprises an entrance for the heat storage agent, and is configured to guide the heat storage agent discharged through the discharge adjusting valve into a hollow interior formed by a shell component; 
 the air entrance and exit pipes, the row of air heating pipes and the connecting pipes are provided in the hollow interior of the air heater; 
 the row of air heating pipes comprises a plurality of heating pipes, an upper linking pipe, and a lower linking pipe, the heating pipes are filled with a porous material for dividing compressed air with a first temperature from the thermal power generating module into fine flows and directing the compressed air to flow against the heat storage agent discharged outside the heating pipes to exchange heat to heat the compressed air to a second temperature; 
 the connecting pipes are configured to join the air heating pipes, and are joined with the air entrance and exit pipes, wherein the compressed air with the first temperature enters and the compressed air with the second temperature exits the connecting pipes through the air entrance and exit pipes; and 
 the air entrance and exit pipes are configured to allow compressed air to flow between the thermal power generating module and the connecting pipes. 
 
     
     
       12. The Brayton solar thermal power unit of  claim 11 , wherein the air heater further comprises:
 a flow guiding bar for directing flow of particles in the hollow interior or directing the flow of particles along the inner wall of the shell, is provided in the hollow interior of the air heater with the high-temperature particle moving bed, is configured for stirring the heat storage agent discharged into the hollow interior. 
 
     
     
       13. The Brayton solar thermal power unit of  claim 11 , wherein the air heater further comprises:
 a star rotating valve for controlling the flow of particles discharged, is provided below the row of air heating pipes, wherein a flow rate of the heat storage agent in the air heater with the high-temperature particle moving bed is adjustable by adjusting the rotation speed of the star rotating valve so that the temperature of the air outputted by the air heater reaches and remains stable at a required temperature. 
 
     
     
       14. The Brayton solar thermal power unit of  claim 11 , wherein each heating pipe in the row of air heating pipes is a silicon carbide ceramic pipe, and each silicon carbide ceramic pipe is filled with porous carbide ceramic material with a surface-to-volume ratio of over 500. 
     
     
       15. An air heater, comprising: a particle entrance component, a row of air heating pipes, connecting pipes joining the air heating pipes, and air entrance and exit pipes, wherein
 the particle entrance component is provided at the top of the air heater with a high-temperature particle moving bed, comprises an entrance for heat storage agent, is configured to direct the heat storage agent discharged via a discharge control valve into a hollow interior formed by a shell; 
 the air entrance and exit pipes, the row of air heating pipes and the connecting pipes are provided in the hollow interior of the air heater; 
 the row of air heating pipes comprises a plurality of heating pipes and an upper linking pipe and a lower linking pipe, each of the heating pipes is filled with a porous material which divides compressed air with a first temperature from a thermal power generating module into fine flows and directs the fine flows to flow against heat storage agent discharged outside the heating pipes to exchange heat to heat the compressed air to a second temperature; 
 the connecting pipes are configured to join the row of air heating pipes, and are joined with the air entrance and exit pipes, wherein the compressed air with the first temperature enters and the compressed air with the second temperature exits the connecting pipes through the air entrance and exit pipes; and 
 the air entrance and exit pipes are configured to allow compressed air to flow between the thermal power generating module and the row of air heating pipes. 
 
     
     
       16. A method of controlling temperature of heated heat storage agent in a Brayton solar thermal power unit with heat storage, comprising:
 providing a Brayton solar thermal power unit with heat storage which comprises: a heater of heat storage agent and a heat storage agent flow adjusting module; the heat storage agent flow adjusting module is capable of obtaining heat storage agent, and discharging the heat storage agent into the heater via a flow control valve set at the bottom of the heat storage agent flow adjusting module; the heater comprises a multi-threaded screw sleeve made of high temperature materials, the multi-threaded screw sleeve has a hollow interior, a plurality of spiral slideways are provided in an inner wall of the multi-threaded screw sleeve for receiving the heat storage agent from the heat storage agent flow adjusting module, the heat storage agent discharged in the multi-threaded screw sleeve is heated by solar radiation concentrated in the hollow interior; 
 sensing a temperature of the heat storage agent outputted by the heater; 
 comparing the sensed temperature with a pre-determined temperature threshold; in response to a determination that the sensed temperature is inconsistent with the temperature threshold, adjust a rotation speed of the rotating multi-threaded screw sleeve to change a falling speed of the heat storage agent in the heater, and adjust an opening of the flow control valve of the heat storage agent flow adjusting module to change the flow of the heat storage agent in the heater, until it is determined the sensed temperature of the heat storage agent is consistent with the pre-determined temperature threshold. 
 
     
     
       17. The Brayton solar thermal power unit of  claim 8 , wherein the ceramic microspheres is made of one of alumina, mullite, or quartz, or a mixture of any combination of alumina, mullite, or quartz.